A fundamental security issue is confidently identifying one user or device to another user or device. In one example, a first device sends to a second device one or more credentials, and the second device identifies the first device as suitable for granting access to restricted resources.
In some cases, a two-factor identification protocol may be provided, such as where additional security is desirable. For example, a smart phone may create a two-channel connection to a server or other similar device. On the first channel, the smart phone provides data or voice to carry out the purpose of the connection. On the second channel, the smartphone transmits credential information. This allows the server to determine with some level of confidence that the device is authorized to use certain resources.